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  • Home

  • A) Acronyms & Definitions
  • B) References
  • C) Additional Resources

  • A) Foundational Concepts
  • B) System Curves
  • C) Rotodynamic Pump Types
  • D) Rotodynamic Pump Curves
  • E) Pump Principles
  • F) Positive Displacement Pump Types
  • G) Positive Displacement Pump Principles
  • H) Positive Displacement Pump Curves
  • I) Operating Point

  • A) Water
  • B) Solids and Slurries
  • C) Viscosity
  • D) Other Fluids

  • A) Pipe Frictional Losses
  • B) Losses in Valves, Fittings, and Bends
  • C) Losses With Other Fluids
  • D) Losses in Nozzles
  • E) Losses With Paper Stock

  • A) Steel Pipe
  • B) Stainless Steel Pipe
  • C) Ductile Iron Pipe
  • D) Non-Ferrous Pipe and Tube
  • E) Plastic PVC Pipe
  • F) Flange Dimensions
  • G) Motor Dimensions

  • A) Unit Conversions
  • B) Kinematic & Dynamic Viscosity Conversion
  • C) Pipe Friction Loss Calculator
  • D) Line Shaft Bearing Loss Calculator
  • E) Horizontal Tank Volume Calculator
  • F) Vertical Tank Volume Calculator
  • G) Spherical Tank Volume Calculator
  • H) Atmospheric Pressure Calculator

  • Releases
  • Members and Contributors

Positive Displacement Pump Types

The Hydraulic Institute standardizes positive displacement (PD) pump types, definitions and nomenclature. PD pumps move liquid by repeatedly trapping a fixed volume and forcing (displacing) it from suction to discharge through reciprocating or rotary action. PD pumps may be classified into reciprocating types, which use pistons, plungers and diaphragms, and rotary types, which utilize meshing components, such as, screws, gears, lobes and vanes. The description for each rotodynamic pump type, and the related industry standard are included. The description for each PD pump type, and the related industry standard are summarized on this page.

For descriptions on rotodynamic pumps refer to the Rotodynamic pump types.

Index

Pump Types - Rotary Positive Displacement
Pump Types - Reciprocating Positive Displacement

Pump Types - Rotary Positive Displacement
Pump Types - Rotary Positive Displacement
Acronym Pump Description Reference
Circumferential piston ANSI/HI 3.1-3.5
Gear type - sealless ANSI/HI 4.1-4.6
Gear, external ANSI/HI 3.1-3.5
Gear, internal with crescent ANSI/HI 3.1-3.5
Gear, internal without crescent ANSI/HI 3.1-3.5
Lobe, single ANSI/HI 3.1-3.5
Lobe, three ANSI/HI 3.1-3.5
Piston, axial ANSI/HI 3.1-3.5
Screw type - Sealless ANSI/HI 4.1-4.6
Screw, single (progressing cavity) ANSI/HI 3.1-3.5
Screw, three (untimed) ANSI/HI 3.1-3.5
Screw, two (timed) ANSI/HI 3.1-3.5
Tube, flexible (peristaltic) ANSI/HI 3.1-3.5
Vane type - sealless ANSI/HI 4.1-4.6
Vane, flexible ANSI/HI 3.1-3.5
Vane, sliding ANSI/HI 3.1-3.5

Pump Types - Reciprocating Positive Displacement
Pump Types - Reciprocating Positive Displacement
Acronym Pump Description Reference
AOD Air-operated - Bellows - simplex or duplex ANSI/HI 10.1-10.6
AOD Air-operated - Diaphragm - simplex or duplex ANSI/HI 10.1-10.5
Air-operated - piston
Air-operated - plunger
CVMP Controlled volume metering - diaphragm ANSI/HI 7.1-7.5
CVMP Controlled volume metering - piston ANSI/HI 7.1-7.5
Piston - direct acting - single or double acting - simplex or duplex HI 8.1-8.5
Plunger - direct acting - single or double acting - simplex or duplex HI 8.1-8.5
Piston - single or double acting - simplex or multiplex HI 6.1-6.5
Plunger- single or double acting - simplex or multiplex HI 6.1-6.5

Last updated on August 31, 2026

Related topics

A) Foundational Concepts
B) System Curves
C) Rotodynamic Pump Types
D) Rotodynamic Pump Curves
E) Pump Principles
G) Positive Displacement Pump Principles
H) Positive Displacement Pump Curves
I) Operating Point